1. Field of Invention
The present invention relates to the field of modification treatment of a metallic or nonmetallic surface, and in particular, to a method for preparing a diamond carbon membrane on a surface of stainless steel.
2. Description of Related Arts
A diamond film, which has such advantages as high hardness, resistance to wear, resistance to corrosion and high temperature resistance, may be applied onto a tool or drill, not only resulting in extension of the tool life by ten times to dozens of times, but also significant improvement of the cutting efficiency. In the conventional method for preparation of diamond, such stringent conditions as high pressure and high temperature are required. Since 1980s, the methods for preparing the diamond film at the moderate conditions of low temperature (600-1000° C.) and low pressure (vacuum or atmospheric pressure) have been developed. The current methods for synthesizing the diamond film primarily include chemical vapor deposition, physical vapor deposition, liquid deposition, polymer pyrolysis and the like. The vapor deposition suffers from such major disadvantages as low growth efficiency, complex deposition apparatus, and high cost, being unsuitable for preparation of diamond film on the substrate with a large area and a complex shape. The liquid deposition suffers from such disadvantages as low rate and efficiency of deposition, and low level of the formed diamond structure phase.
By searching the prior art, liquid electrodeposition of diamond-like film on the stainless steel is found in Electrochemistry, vol. 13, No. 1, pp. 58-62, February 2007, which suggested that, the methanol organic liquid is used as a carbon source by pulse electrochemical deposition to prepare the diamond-like film on the stainless steel surface, having poor crystallinity although there is a characteristic peak like diamond in its Raman spectrum. By searching, the study on the surface of diamond-like film prepared from polymer pyrolysis is found in J. Chin. Electr. Microsc. Soc. 22 (6): 547-548, 2003, which suggested that polyphenyl carbonate dissolved in the organic solvent is applied onto the surface of monocrystalline silicon and is treated at high temperature under inert gas protection upon volatilization of the solvent, to give the diamond-like film primarily including amorphous graphite carbon and possibly trace but undetectable diamond phase.
Preparation of diamond or diamond-like film on the stainless steel surface by polymer pyrolysis has not been reported. In the patent publication No. U.S. Pat. No. 1,421,477A, the prepared carbonaceous mesophase had optical anisotropy, favorable self-sintering and self-bonding properties. In particular, the biomass-derived carbonaceous mesophase film may be converted into the diamond or diamond-like film under hydrogen selective etching, induction and catalytic action during heating. The stainless steel, specially the most widely used stainless steel 304 and 316, contains substantial elements such as iron, nickel and chromium, resulting in a certain catalytic effect on synthesis of the diamond carbon membrane.